[Ojopie Sentimental (Ojo)] Hitozuma Pet ~Hitozuma ga Papakatsu Sex ni Hamari Otto Kounin de Otoko-tachi no Pet ni Naru Hanashi~ Zenpen [English] [carltranslates]
It's quite rare you'll ever need to level digital releases, and if you do, it's usually very minimal. Checking the raws in Photoshop, I wouldn't even create levels layers for this.
Good indicators are the black and white peaks. If you see them at the very beginning and end of the levels graph, it usually means the blacks and the whites are already perfectly set.
edit: You should check your export settings or your color settings then. Your pages are A LOT darker than the raws.
@cutegyaru, i didn't mess with the levels at all, it's just as in the raws edit: these are my export settings: https://i.imgur.com/W3vLRYB.png don't see anything that should be causing darker images.